This invention relates to friction brakes such as disc brakes, which brakes are actuated by a servo-motor operated by pressure oil, and more particularly to an arrangement for producing temporarily a soft connection of the friction surfaces.
When connecting the friction surfaces of a disc brake actuated by a pressure oil servo-motor, there is often difficulty in avoiding pressure peaks and torque peaks. It is frequently desirable that the connection of the brake discs during a definite period should allow slip in oder to provide a definitely soft connection with limited torque. In general this problem has been solved by providing a pressure modulating arrangement on, or in connection with the servo-motor which for normal purposes may be said to be acceptable although it is not a good solution.
The problems described in the preceding paragraph are of particular importance in the friction brakes associated with the operation of a hydraulic torque converter such as for example the friction brake which controls the operation of the guide member.